Arrangement and method for automatically removing a strip consisting of dark meat from a fish fillet

ABSTRACT

An arrangement for automatically removing a strip of dark meat from a fish fillet has a conveying unit for transporting the fish fillet from an inlet to an outlet area in a transport direction along a transport path. Starting from the inlet area, successively along the transport path, are provided: a first means for detecting dark meat; a first cutting apparatus for removing a middle partial strip of dark meat; a means for opening up the fillet such that cut surfaces of a ventral-side partial and of a dorsal-side partial strip of dark meat point upwards; a cutting unit for removing the partial strips, the cutting unit comprising second and third cutting apparatuses for removing the ventral and dorsal-side partial strips. A control device is connected to the detecting means and the cutting apparatuses, and all cuts are based on information from the detecting means. A corresponding method is provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. National Stage of PCT/EP2019/058973 filedApr. 9, 2019, the content is incorporated herein by reference in itsentirety.

FIELD OF THE INVENTION

The invention relates to an arrangement, designed and configured forautomatically removing a strip consisting of red meat, the so-calleddark meat, from a fish fillet.

The invention also relates to a method for automatically removing astrip consisting of red meat, the so-called dark meat, from a fishfillet.

BACKGROUND OF THE INVENTION

When processing tuna and similar species that undertake long-distancemigrations and accordingly have a particular muscle structure, dueconsideration must be given to the special characteristics of the musclestructure. Taking tuna as an example, the fish fillets detached from theskeleton, and in particular from the backbone/central bone, show aninhomogeneous muscle structure. This means that there are differentproportions of meat and muscle. In addition to the “normal” muscle meat,which is usually light-coloured, the fish fillets also have a region ofdark muscle meat starting from the region of the (removed) central bonetowards the skin side. The dark muscle meat, the so-called red meat, isof inferior quality in terms of taste such that it should be removed ascompletely as possible.

The region of the central bone divides the fish fillet into a notionaldorsal-side partial fillet and a ventral-side partial fillet. In otherwords, the region of the fish fillet which extends upwards, startingfrom the central bone towards the dorsal fins, is referred to as thedorsal-side partial fillet, while the region of the fish fillet whichextends downwards, starting from the central bone towards the abdominalcavity, is referred to as the ventral-side partial fillet. The term“fish fillet” refers not only to such products which no longer have anybones at all but also, in particular, to such products in which at leastthe central bone is removed so that the strip of red meat on the sidedirected away from the skin side is exposed. Accordingly, the fishfillets are processed with the skin side down.

The spread of the red meat, however, also referred to as dark meat,within the fish fillet makes it impossible to remove it with commoncutting apparatuses in which, for example, two circular knives set in aV-shape to each other cut a V-shaped strip from the fish fillet. Thespread of the red meat actually deviates from a classic V-shape andvaries from fish fillet to fish fillet. Accordingly, a simple V-cutresults either in red meat remaining in the fish fillet or light musclemeat being removed in addition to the red meat. In other words, theprocessing results when removing the red meat with common cuttingapparatuses are not accepted due to the yield losses on the one hand andthe error rates on the other hand, such that the processing of tuna orcomparable species has previously been carried out manually whenremoving the red meat.

To make it easier for people to remove the red meat, the products to beprocessed are cooked before processing. Cooking brings about a colourchange to the effect that the “normal” muscle meat becomes (even)light(er), while the dark red meat becomes even darker (almost black).The colour change enables the person to differentiate better between thestructures and the meat contents, and in particular to identify thespread of the red meat better within the product. However, the manualremoval of the red meat from the fish fillet has various disadvantages.On the one hand, manual removal is very time-consuming and thereforecost-intensive, especially as cooking necessitates an additional andtime-intensive work step. On the other hand, manual removal leads toyield losses. In addition, the cutting result depends substantially onthe experience and skill of the person who processes the product.

SUMMARY OF THE INVENTION

The object of the invention is therefore to create an arrangement whichensures automatic removal of the strip of red meat from fish filletsreliably and with optimised yield. The object of the invention is alsoto create a corresponding method.

This object is achieved by an arrangement of the type referred tohereinbefore, in that it is characterised by a conveying unit fortransporting the fish fillet to be processed from an inlet area of thefish fillet into the arrangement to an outlet area of the fish filletout of the arrangement in transport direction T along a transport pathand, starting from the inlet area in the direction of the outlet areasuccessively along the transport path, a first means for detecting redmeat in the fish fillet to be processed, a first cutting apparatus forremoving a middle, central partial strip of red meat from the fishfillet, a means for opening up the fish fillet freed from the middlepartial strip in such a manner that the cut surfaces of a ventral-sidepartial strip of red meat still attached to the fish fillet and of adorsal-side partial strip of red meat still attached to the fish fillet,which are produced by the first cutting apparatus, point upwards awayfrom the conveying unit, a cutting unit for removing the ventral-sideand the dorsal-side partial strip of red meat from the fish fillet, thecutting unit comprising a second cutting apparatus for removing theventral-side partial strip and a third cutting apparatus for removingthe dorsal-side partial strip, as well as a control device, at least themeans for detecting red meat and the three cutting apparatuses beingconnected to the control device in such a manner that all cuts can bemade based on the data and/or information determined by the means fordetecting red meat. Due to the arrangement according to the invention,it is possible to free fish fillet containing red meat, in particulartuna fillet, efficiently and precisely from red meat by machine. Due tothe three cutting apparatuses arranged one behind the other in transportdirection T, the strip of red meat to be removed can be cut out of thefish fillet step by step, in that a first incision goes into the depth,towards the skin side of the fish fillet which is lying flat with theskin side on the conveying unit and the second and third incisions gomainly into the ventral region or into the dorsal region respectively,as the means for opening up or unfolding the fish fillet brings thepartial fillets, i.e. the ventral-side section and the dorsal-sidesection of the fish fillet, into a position which allows the second andthird cutting apparatus to penetrate the fish fillets, virtuallyparallel to the skin side. This allows the strips of red meat to beremoved individually for each fish fillet, independently of theparticular spread of the red meat within the fish fillet. Furthermore,this can also be used in particular to process raw, i.e. uncooked fish.

In a preferred development of the invention, in transport direction T asecond means for detecting the remaining red meat in the fish fillet tobe processed is arranged between the means for opening up the fishfillet and the cutting unit, wherein the second means for detecting redmeat is also connected to the control device. This allows the second andthird cutting apparatus to be controlled even more precisely with regardto their incision. After the first cut and the removal of a firstpartial strip of red meat, the second means for detecting the remainingred meat detects the exact spread of the remaining red meat in theventral region and in the dorsal region so that complete andyield-optimised removal of the red meat is improved.

Advantageously, in transport direction T, a handling device forautomatically aligning the fish fillet to be processed on the conveyingunit is arranged between the first means for detecting red meat, whichis arranged in the inlet area, and the second cutting apparatus forremoving the middle, central partial strip, the handling device alsobeing connected to the control device. Due to the handling device, eachfish fillet to be processed can be optimally orientated in relation tothe first cutting apparatus regarding alignment of the strip of red meatin order to optimise the cutting result of the first cutting apparatus.

A preferred embodiment is characterised in that the handling devicecomprises a robotic mechanism, e.g. a delta kinematics mechanism, withan alignment tool. With this embodiment, the fish fillets can be moved,and in particular also rotated, virtually freely in all directions whichensures individual and precise positioning of the fish fillet with astrip of red meat lying centrally on the conveying unit and alignedsubstantially parallel to transport direction T before the first cut,regardless of the starting location/starting position of the particularfish fillet on the conveying unit.

The first cutting apparatus preferably comprises two circular knives setin a V-shape at a fixed angle to each other and drive means for thecircular knives, the two circular knives being designed to be verticallyand horizontally adjustable. This ensures simple but neverthelessprecise and efficient removal of the middle, central partial strip ofred meat.

Especially preferably, the first cutting apparatus is arranged on arobotic mechanism, e.g. a delta kinematics mechanism, by means of whichthe position of the first cutting apparatus relative to the conveyingunit is adjustable at least vertically and horizontally, the roboticmechanism also being connected to the control device. Particularly incombination with the handling device, this ensures optimum alignment ofthe fish fillets with the circular knives and of the circular kniveswith the fish fillets for precise incision.

Expediently, the second and the third cutting apparatus each comprisetwo circular knives set in a V-shape to each other as well as drivemeans for the circular knives. With this embodiment, the ventral-sideand the dorsal-side partial strips of red meat can be removedparticularly efficiently and precisely.

A particularly advantageous embodiment is characterised in that thesecond and the third cutting apparatus each has a knife carrier to whichtwo knife units are assigned, each knife unit comprising a circularknife and a drive means for rotationally driving the circular knifeabout a central axis of rotation M₁, M₂, the two circular knives beingset substantially in a V-shape to each other in a position enclosing anangle α and it being possible to set the size of the angle α by anadjustable arrangement of the knife units on the knife carrier, theoffset of the two central axes of rotation M₁, M₂ to each other beingequal to zero in transport direction T and the two knife units beingdesigned and configured to be adjustable exclusively synchronously witheach other. This means that each cutting apparatus can be adjusted andadapted to the individual spread of the red meat in the ventral-side anddorsal-side section to ensure yield-efficient removal of the partialstrips and prevents incorrect incisions.

The second and the third cutting apparatus are preferably arranged onebehind the other in transport direction T and each on a roboticmechanism, e.g. a delta kinematics mechanism, the robotic mechanismsalso being connected to the control device. With the robotic mechanism,the cutting apparatuses can be optimally positioned in relation to thefish fillets to be processed before and during cutting for improvedincision.

An especially preferred development is characterised in that theconveying unit comprises a plurality of conveying elements, a firstconveying element in the region of the first cutting apparatus being arotationally driven double belt with a gap running centrally andparallel to the transport direction T, while a second conveying elementin the region of the cutting unit is a rotationally driven segment chainwhich is triangular in cross-section. With this embodiment of theconveying unit, said conveying unit is adapted to the relevant cuttingapparatuses in such a manner that the fish fillets are each placed in anoptimum location/position in relation to the cutting apparatus.

Advantageously, the double belt and the segment chain form a continuousconveying unit along the transport path in transport direction T, thesegment chain engaging in the double belt from below through the gap, atleast in the transition region from the double belt to the segmentchain, for transferring the fish fillets from the double belt. In thetransition region, the fish fillet is thus in contact with the doublebelt on the one hand and the segment chain on the other hand. Thisensures continuous conveying of the fish fillets through the entirearrangement.

Especially preferably, the segment chain forms the means for opening upthe fish fillets. This eliminates the need for additional means foropening up or unfolding. The dual function of the segment chain asconveying means and means for opening up ensures simple but neverthelessreliable positioning of the fish fillets below the second and thirdcutting apparatus. The segment chain, which is at least partlytriangular in cross-section, causes the partial fillets to fold so farto the side and downwards by the force of gravity alone on leaving thedouble belt that the cut surfaces formed by the first cut still pointupwards or at least obliquely upwards so that the second and the thirdcutting apparatus can penetrate into the ventral region or the dorsalregion respectively—substantially parallel to the skin side—i.e. into aregion in which the first cutting apparatus cannot penetrate or cannotpenetrate without loss of yield.

Advantageously, the segment chain has spike-like protrusions, on itsupper side pointing in the direction of the cutting unit, for fasteningthe fish fillets on the segment chain. This ensures additional fasteningof the fish fillets on the segment chain, as a result of which the fishfillets are secured against slipping on the segment chain and can betransported accurately positioned. Another effect of the spike-likeprotrusions is that they assist the partial fillets to bend on bothsides of the segment chain, which is triangular or more accuratelyroof-shaped in cross-section, i.e. they help to open up the fishfillets.

In a preferred development, devices for holding the fish down areassigned to the segment chain at least in the region of the cuttingunit, in such a manner that the opened up fish fillets can be fastenedon both sides of the segment chain, between device for holding the fishdown and segment chain, at least when removing the ventral-side anddorsal-side partial strips. Due to transporting the fish fillets intransport direction T, the fish fillets or the partial fillets hangingdown on both sides of the segment chain thread between the segmentchain, which supports from below, and the device for holding the fishdown, which holds from above, as a result of which the partial filletsare held securely and precisely during cutting. Together with thesegment chain, the devices for holding the fish down thus ultimatelyform the means for opening up or they assist the segment chain at leastduring the opening up process, as they reliably hold the partial filletsin the spread position.

Preferably, fastening means are provided in the region of the doublebelt, in such a manner that the fish fillet can be fastened on thedouble belt at least when removing the middle, central partial strip. Inother words, the fish fillet lying with the skin side flat on the doublebelt is optionally pressed against the double belt from above and/orsucked onto the double belt from below.

In an especially preferred development, a second cutting unit,corresponding to the first cutting unit, is arranged downstream of saidfirst cutting unit, which comprises the second and third cuttingapparatus, in transport direction T, the second cutting unit also beingconnected to the control device. In other words, the cutting unit isduplicated so that two incisions for removing the ventral-side partialstrip can be made successively in each case and two incisions forremoving the dorsal-side partial strip can be made in each case. On theone hand, this allows the processing speed to be increased. On the otherhand, the accuracy when removing the strip of red meat from a fishfillet is improved.

Expediently, a third means for detecting red meat is arranged downstreamof the first cutting unit and upstream of the second cutting unit intransport direction T, the third means for detecting red meat also beingconnected to the control device. This embodiment also improves thecutting accuracy and thus the processing result.

A preferred embodiment is characterised in that suction means forextracting the removed partial strips are arranged in the region of eachcutting apparatus. As a result of this development, the cutting regionis always freed of partial strips or parts that have already beenremoved, which particularly improves the detection of (remaining) redmeat by downstream means for detecting red meat.

The object is achieved by a method which is characterised by thefollowing steps: automatically transporting the fish fillet to beprocessed along a transport path from an inlet area to an outlet area intransport direction T by means of a conveying unit, automaticallydetecting the red meat in the fish fillet to be processed using a meansfor detecting red meat, automatically cutting a middle, central partialstrip of red meat from the fish fillet using a first cutting apparatus,automatically opening up the fish fillet freed from the middle, centralpartial strip using a means for opening up, in such a manner that thecut surfaces of a ventral-side partial strip of red meat still attachedto the fish fillet and a dorsal-side partial strip of red meat stillattached to the fish fillet, which are formed when removing the middle,central partial strip, point upwards away from the conveying unit,automatically cutting the ventral-side and dorsal-side partial stripfrom the fish fillet using a second and a third cutting apparatus, thecutting apparatuses being controlled using a control device based on thedata and/or information determined by the means for detecting red meat.

Preferably, the strip of red meat is automatically cut from the fishfillet in at least three steps, first the middle, central partial stripbeing cut from the fish fillet and subsequently first the ventral-sidepartial strip and then the dorsal-side partial strip or first thedorsal-side partial strip and then the ventral-side partial strip of redmeat being cut from the fish fillet. The order in which the cuts aremade for removing the ventral-side partial strip and for removing thedorsal-side partial strip is arbitrary.

Advantageously, the cutting, first of the ventral-side partial strip andthen the dorsal-side partial strip or vice versa, is repeated in afourth and fifth step by additional cutting apparatuses along thetransport path, the red meat in the fish fillet to be processed beingautomatically detected again before the fourth and fifth step using ameans for detecting red meat. In other words, the second and the thirdcut are each repeated at least once, if necessary twice or severaltimes, in order to improve the accuracy by repeating the process, eachtime with renewed and thus more precise detection of the red meat stilllocated in the fish fillet.

Preferably, each fish fillet is fastened on the conveying unit duringcutting of the partial strip.

Especially preferably, all cuts of all partial strips are made bycircular knives set in a V-shape to each other.

Optionally, the partial strips removed by cutting are extracted bysuction.

Especially preferably, the method is carried out using an arrangement asdisclosed above.

Further advantages arising from this have already been described inconnection with the arrangement, which is why reference will be made tothe relevant passages to avoid repetitions.

BRIEF DESCRIPTION OF THE DRAWINGS

Further expedient and/or advantageous features and developments of thearrangement and the method are disclosed herein. Especially preferredembodiments of the arrangement and the method are explained in greaterdetail with reference to the attached drawing. The drawing shows:

FIG. 1 is an axial cross-section through a fish fillet with a centralbone and the skin side opposing the central bone;

FIG. 2 is a view of the fish fillet according to FIG. 1 without thecentral bone, with the skin side lying on a conveying unit;

FIG. 3 is a schematic illustration of a preferred embodiment of anarrangement for automatically removing a strip consisting of red meatfrom a fish fillet according to FIG. 2;

FIG. 4 is an enlarged illustration of a double belt as part of aconveying unit with first means for detecting red meat arranged abovethe double belt, a first cutting apparatus for removing a middle,central partial strip of red meat and a handling device forautomatically aligning the fish fillet on the double belt;

FIG. 5 is aa sectional view through a segment chain as part of aconveying unit with a fish fillet freed from the middle, central partialstrip of red meat in the opened position on the segment chain;

FIG. 6 is an enlarged illustration of the transition region from thedouble belt to the segment chain with a second means for detecting redmeat and a second cutting apparatus as part of a cutting unit forremoving a partial strip of red meat located on the ventral side ordorsal side of the fish fillet;

FIG. 7 is an enlarged illustration in perspective view of the second anda third cutting apparatus above the segment chain and devices forholding the fish down; and

FIG. 8 is an illustration of the apparatus according to FIG. 7 viewed intransport direction T.

DETAILED DESCRIPTION OF THE INVENTION

The arrangement illustrated in the drawing is used for automaticallyremoving a strip of red meat from a fish fillet. The invention isdescribed using the example of the tuna which has the dark meat to beremoved. However, the invention is equally applicable to other fishspecies which have a strip of red meat (dark meat) in their fish filletin addition to the “normal” muscle meat. These are in particular suchfish species which have this special muscle structure due to theircharacteristic of covering long distances.

To facilitate better understanding, the muscle structure of a tuna or afish fillet 10 and of comparable species will first be explained basedon FIGS. 1 and 2. FIG. 1 shows a single fish fillet 10 of a tuna withtwo fillets. The single fish fillet 10 still has a central bone 11 inthe illustration. Starting from the central bone 11, the dorsal-sidepartial fillet 12 extends upwards towards a dorsal fin which is notshown. Starting from the central bone 11, the ventral-side partialfillet 14 extends downwards towards an abdominal cavity 13 (onlyindicated). The skin side 15 of the fish fillet 10 is located on theside opposite the central bone 11. The fish fillet 10 consists mainly of“normal” light muscle meat 16. However, starting from the central bone11, a partially asymmetrical strip 17 of red meat extends towards theskin side 15. This strip 17 has an individual spread within the musclemeat 16 for each fish fillet 10.

FIG. 2 shows the fish fillet 10 according to FIG. 1 without the centralbone 11, the fish fillet 10 lying on the skin side 15. As a result, thestrip 17 of red meat points upwards, the strip 17 being orientedsubstantially in transport direction T in the longitudinal direction ofthe fish fillet 10.

The arrangement 18 illustrated from FIG. 3 onwards is designed andconfigured for automatically removing a strip 17 consisting of red meat,the so-called dark meat, from a fish fillet 10. This arrangement 18 ischaracterised according to the invention in that it is characterised bya conveying unit 19 for transporting the fish fillet 10 to be processedfrom an inlet area E of the fish fillet 10 into the arrangement 18 to anoutlet area A of the fish fillet 10 out of the arrangement 18 intransport direction T along a transport path and, starting from theinlet area E in the direction of the outlet area A successively alongthe transport path, a first means 20 for detecting red meat in the fishfillet to be processed 10, a first cutting apparatus 21 for removing amiddle, central partial strip of red meat from the fish fillet 10, ameans 22 for opening up the fish fillet 10 freed from the middle partialstrip in such a manner that the cut surfaces F₁ and F₂ of a ventral-sidepartial strip of red meat still attached to the fish fillet 10 and of adorsal-side partial strip of red meat still attached to the fish fillet10, which are produced by the first cutting apparatus 21, point upwardsaway from the conveying unit 19, a cutting unit 23 for removing theventral-side and the dorsal-side partial strip of red meat from the fishfillet 10, the cutting unit 23 comprising a second cutting apparatus 24for removing the ventral-side partial strip and a third cuttingapparatus 25 for removing the dorsal-side partial strip, as well as acontrol device 26, at least the means 20 for identifying red meat andthe three cutting apparatuses 21, 24, 25 being connected to the controldevice 26, in such a manner that all cuts can be made based on the dataand/or information determined by the means 20 for detecting red meat.

When taken on their own or in combination with each other, the featuresand developments described below illustrate preferred embodiments. It isexpressly pointed out that features which are summarised in the claimsand/or the description and/or the drawing or are described in a commonembodiment can also further develop the arrangement 18 described abovein a functionally independent manner.

The conveying unit 19 comprises drive means, not explicitly shown, forrotational and preferably continuous drive. The drive means arepreferably also connected to the control device 26. The first means 20for detecting red meat may, for example, comprise a camera. Instead ofthe camera or in addition to the camera, the means 20 may also comprisean X-ray apparatus or other apparatus by means of which the size and/orextent and/or alignment and/or orientation and/or distribution of thestrip 17 consisting of red meat can be detected within the muscle meat16.

Preferably, in transport direction T, a second means 27 for detectingthe remaining red meat in the fish fillet 10 to be processed is arrangedbetween the means 22 for opening up the fish fillet 10 and the cuttingunit 23, the second means 27 for detecting red meat also being connectedto the control device 26. In other words, the second means 27 fordetecting red meat is located between the first cutting apparatus 21 andthe cutting unit 23. The second means 27 for detecting red meat isdesigned and configured in line with the first means 20 for detectingred meat.

FIG. 4 is an enlarged view of the inlet area E of the fish fillet 10.The conveying unit 19 comprises a plurality of conveying elements, afirst conveying element 28 in the region of the first cutting apparatus21 being a rotationally driven double belt 29 with a gap 30 runningcentrally and parallel to the transport direction T, while a secondconveying element 31 in the region of the cutting unit 23 is arotationally driven segment chain 32 which is triangular incross-section. The double belt 29 may be made up of two completelyseparate belts with separate guiding and drive elements. In otherembodiments, two partial belts may be arranged at a distance from eachother on the same guiding and drive elements. The gap 30 may extend overa part of the length of the double belt 29 or over the entire length ofthe double belt 29, the gap 30 oriented in the transport direction Tbeing arranged centrally in all embodiments, in such a manner that thegap 30 divides the double belt 29 symmetrically. In particular, in theevent that the gap 30 extends over the entire length of the double belt29, the gap 30 may be covered at least partially by a cover element 33.

The segment chain 32 is arranged overlapping the double belt 29. Thismeans that the segment chain 32 along the transport path already startsbefore the double belt 29 ends, so that each fish fillet 10 in theoverlap region is both located on the double belt 29 and is alsosupported by the segment chain 32. In the overlap region, the coverelement 33 also has a gap 34 which allows the segment chain 32 toproject, at least with its tips 35 of the individual segments 36upwardly directed towards the cutting apparatus 21, through the gap 30of the double belt 29 and the gap 34 of the covering element 33 beyondthe plane defined by the double belt 29 (in relation to the surface ofthe double belt 29). In other embodiments, the segment chain 32 mayitself lie with its tips 35 in or below the plane defined by the doublebelt 29. The double belt 29 and the segment chain 32 are individuallycontrollable by means of the control device 26. Preferably, the doublebelt 29 and the segment chain 32 are synchronously controllable by meansof the control device 26, in such a manner that they are driven, forexample, at the same drive speed.

In transport direction T, a handling device 37 for automaticallyaligning the fish fillet 10 to be processed on the conveying unit 19 isarranged between the first means 20 for detecting red meat, which isarranged in the inlet area E, and the second cutting apparatus 21 forremoving the middle, central partial strip, said conveying unit beingarranged in the example on the double belt 29, and the handling device37 also being connected to the control device 26. The handling device 37preferably comprises a robotic mechanism, e.g. a delta kinematicsmechanism, with an alignment tool which is not explicitly shown. Thealignment tool may comprise, for example, gripping and/or suction means,using which the fish fillet 10 can be offset on the double belt 29 intransport direction T and in particular transversely to transportdirection T and, above all, can also be rotated about a vertical axis sothat the strip 17 of red meat is located at least partially, butpreferably completely, centrally in the region of the gap 30. Especiallypreferably, the alignment tool may comprise, for example, a plunger orthe like by means of which the fish fillet 10 can be moved and/orrotated while lying on the double belt 29.

The handling device 37 is particularly designed and configured toautomatically align the fish fillets 10 on the double belt 29, in such amanner that the fish fillets 10 are pre-positioned on the segment chain32 with regard to their location/position. The handling device 37 mayalso be especially preferred if the first cutting apparatus 21 comprisestwo circular knives 38, 39 set in a V-shape at a fixed angle to eachother and drive means 40, 41 for the circular knives 38, 39, the twocircular knives 38, 39 being designed to be vertically and horizontallyadjustable. It may be possible to adjust the circular knives 38, 39manually or automatically. Especially preferably, the first cuttingapparatus 21 is arranged on a robotic mechanism 42, e.g. a parallelkinematics mechanism, by means of which the position of the firstcutting apparatus 21 relative to the conveying unit 19, thus in theexample relative to the double belt 29, is adjustable at leastvertically and horizontally, the robotic mechanism 42 also beingconnected to the control device 26.

Optionally, fastening means 43 are provided in the region of the doublebelt 29, in such a manner that the fish fillet 10 can be fastened on thedouble belt 29 at least when removing the middle, central partial strip.In the embodiment illustrated, for example, a pressure roller 44 isprovided which is arranged in transport direction T upstream of thecutting apparatus 21 above the double belt 29 and is alignedtransversely to transport direction T and presses the fish fillet 10onto the double belt 29 from above. A corresponding pressure roller 44or another means for holding fish down may also be arrangedalternatively or additionally in transport direction T downstream of thecutting apparatus 21. Suction units may also be used as fastening means43, using which the fish fillet 10 is sucked onto the double belt 29from below. The or each pressure roller 44 or the like may be activelydriven. The corresponding drive means may be connected to the controldevice 26. The or each pressure roller 44 is preferably drivensynchronously with the double belt 29 with regard to the drive speed.

The double belt 29 and the segment chain 32 form a continuous conveyingunit 19 along the transport path in transport direction T, the segmentchain 32—as described above—engaging in the double belt 29 from belowthrough the gap 30, at least in the transition region Ü from the doublebelt 29 to the segment chain 32, for transferring the fish fillets 10from the double belt 29. The segment chain 32 is made up of a pluralityof segments 36. Each segment 36 is triangular or roof-shaped incross-section (see, for example, FIGS. 5 and 8). On the upper sidepointing in the direction of the cutting apparatuses 24, 25, eachsegment 36 preferably has a spike-like protrusion 45. In otherembodiments, it is possible for only a few of segments 36 to have such aprotrusion 45, each protrusion 45 having possibly only a roughenedsurface or any other means for holding or penetrating the fish fillet10.

Due to its shape and design, the segment chain 32 optionally forms themeans 22 for opening up the fish fillets 10. On the double belt 29, thefish fillets 10 lie with their skin side 15 flat on the double belt 29.As a result of the fish fillets 10 being transferred by the segmentchain 32, the partial fillets 12, 14 drop—assisted by removal of themiddle, central partial strip of red meat—to the side and downwardsafter leaving the double belt 29, so that the partial fillets 12, 14,which are still connected to each other, lie with their skin side 15 onthe surfaces 46, 47, running obliquely downwards, of the segments 36, asa result of which the cut surfaces F₁ and F₂ are brought from a positionfacing each other into a position in which the cut surfaces F₁ and F₂are directed further upwards in the direction of the cutting apparatuses24, 25 (see in particular FIG. 5). Other means 22 for opening up thefish fillets 10 can also be used additionally and separately to thesegment chain 32. For example, means for actively unfolding the partialfillets may be arranged above the segment chain.

Preferably, devices 48, 49 for holding the fish down are assigned to thesegment chain 32 at least in the region of the cutting unit 23, in sucha manner that the opened up fish fillets 10 can be fastened on bothsides of the segment chain 32, between device 48, 49 for holding thefish down and segment chain 32, at least when removing the ventral-sideand dorsal-side partial strips. The devices 48, 49 for holding the fishdown may be, for example, round profiles. Preferably, however, thedevices 48, 49 for holding the fish down are rotationally drivenconveyor belts 50, 51, the guiding surfaces 52, 53 of which arepreferably aligned parallel to the surfaces 46, 47 of the segments 36(see in particular FIG. 8). The distance of the guiding surfaces 52, 53from the surfaces 46, 47 of the segments 36 is adjustable. The devices48, 49 for holding the fish down are preferably designed and configuredto assist the segment chain 32, as means 22 for opening up, as an activemeans of helping to open up the partial fillets 12, 14 and for holdingthe partial fillets 12, 14 in the spread position.

The second and the third cutting apparatus 24, 25 are arranged above thesegment chain 32 with the devices 48, 49 for holding the fish down. Thesecond and the third cutting apparatus 24, 25 each comprise two circularknives 54, 55; 56, 57 set in a V-shape at a fixed angle to each otherand drive means 58, 59; 60, 61 for the circular knives 54 to 57. In asimple embodiment, the cutting apparatuses 24, 25 may be designed likethe cutting apparatus 21, i.e. with two circular knives 54, 55; 56, 57set in a V-shape at a fixed angle to each other which knives aredesigned to be vertically and horizontally adjustable. Particularly inthe second and third cutting apparatus 24, 25, ring blades, so-calledWhizard knives, may be used instead of the circular knives 54 to 57.

Preferably, the second and the third cutting apparatus 24, 25 each has aknife carrier 62, 63 to which two knife units 64, 65; 66, 67 areassigned, each knife unit 64 to 67 comprising a circular knife 54 to 57and a drive means 58 to 61 for rotationally driving the circular knife54 to 57 about a central axis of rotation M₁, M₂, the two circularknives 54, 55; 56, 57 being set substantially in a V-shape to each otherin a position enclosing an angle α and it being possible to set the sizeof the angle α by an adjustable arrangement of the knife units 64 to 67on the knife carrier 62, 63, the offset of the two central axes ofrotation M₁, M₂ to each other being equal to zero in transport directionT and the two knife units 64, 65; 66, 67 being designed and configuredto be adjustable exclusively synchronously with each other.

The second and the third cutting apparatus 24, 25 are preferablyarranged one behind the other in transport direction T and each on arobotic mechanism 68, 69, e.g. a parallel kinematics mechanism, therobotic mechanisms 68, 69 also being connected to the control device 26.In the embodiment shown, first the second cutting apparatus 24 forremoving the ventral-side strip and subsequently the third cuttingapparatus 25 for removing the dorsal-side partial strip are arranged intransport direction T. However, the order of the cutting apparatuses 24,25 may also be reversed.

A second cutting unit 70, corresponding to the first cutting unit 23, isoptionally arranged downstream of said first cutting unit 23, whichcomprises the second and third cutting apparatus 24, 25, in transportdirection T, the second cutting unit 70 also being connected to thecontrol device 26. Further cutting units with corresponding design maybe provided. A third means 71 for detecting red meat is arrangeddownstream of the first cutting unit 23 and upstream of the secondcutting unit 70 in transport direction T, the third means 71 fordetecting red meat also being connected to the control device 26. Thethird means 71 for detecting red meat is designed and configured inaccordance with the first means 20 and the second means 27 for detectingthe red meat.

Optionally, suction means 72, 73 for extracting the removed partialstrips are arranged in the region of individual cutting apparatuses 21,24, 25 or each cutting apparatus 21, 24, 25. For example, suction pipesare arranged in transport direction T downstream of the respective pairsof circular knives 38, 39; 54, 55; 56, 57, the suction openings of thesuction pipes being directed contrary to transport direction T. Allcomponents for processing the fish fillets 10, i.e. at least the means20, 27, 71 for detecting red meat and all cutting apparatuses 21, 24,25, are arranged above the conveying unit 19 so that processing of thefish fillets 10 takes place from above.

All components involved in the processing process, i.e. in particularthe means 20, 27, 71 for detecting red meat, all cutting apparatuses 21,24, 25, either directly or via the robotic mechanisms 42, 68, 69, aswell as the handling device 37 and the drive means of the conveyingelements 28, 31 are preferably connected to the control device 26 viawires or wirelessly, the control device 26 comprising, among otherthings, an evaluation unit, at least one memory unit and at least onecontrol module for actively controlling the individual components. Thecontrol device 26 may be designed as a programmable logic controller oras a microprocessor-based controller.

In the following, the method for automatically removing a strip 17consisting of red meat, the so-called dark meat, from a fish fillet 10is explained in greater detail based on the drawing, the method beingcharacterised by the combination of the following steps:

The fish fillets 10 to be processed are transported automatically alonga transport path from an inlet area E to an outlet area A in transportdirection T by means of a conveying unit 19. Along the transport path,first of all a means 20 for detecting red meat automatically detects thered meat in the fish fillet 10 to be processed. Subsequently, a middle,central partial strip of red meat is automatically cut from the fishfillet 10 using a first cutting apparatus 21. After the first cut, thefish fillet 10 freed from the middle, central partial strip using ameans 22 for opening up is automatically opened up, in such a mannerthat the cut surfaces F₁, F₂ of a ventral-side partial strip of red meatstill attached to the fish fillet 10 and a dorsal-side partial strip ofred meat still attached to the fish fillet 10, which are formed whenremoving the middle, central partial strip, point upwards away from theconveying unit 19, In the opened position, the ventral-side anddorsal-side partial strips are automatically cut from the fish fillet 10using a second and a third cutting apparatus 24, 25. To execute theautomated cuts for removing all three partial strips from the fishfillet 10, the cutting apparatuses 21, 24, 25 are controlled using acontrol device 26 based on the data and/or information determined by themeans 20 for detecting red meat.

Preferably, the data and/or information from the drive means for theconveying unit 19 is also used when controlling the cutting apparatuses21, 24, 25. The multi-stage removal of the entire strip 17 of red meatis in the foreground of the method according to the invention. The strip17 of red meat is automatically cut from the fish fillet 10 in at leastthree steps, first the middle, central partial strip being cut from thefish fillet 10 and subsequently first the ventral-side partial strip andthen the dorsal-side partial strip or first the dorsal-side partialstrip and then the ventral-side partial strip of red meat being cut fromthe fish fillet.

Optionally, before the first cut, a handling device 37 is used toautomatically bring the fish fillet 10 into the optimum position inrelation to the cutting apparatus 21, in which position the strip 17 tobe removed is located at least predominantly centrally in the region ofa gap 30 of a double belt 29 and in its longitudinal extension isaligned substantially parallel to transport direction T. To do this, thehandling device 37 is controlled by the control device 26. In the firstautomatic cut, the fish fillet 10 is preferably held on the double belt29 using a fastening means 43 or is pressed onto and/or sucked onto saiddouble belt. After the first cut, the fish fillet 10 is transferred fromthe double belt 29 by a segment chain 32 of the conveying unit 19, thefish fillet 10 automatically opening after leaving the double belt 29 onthe segment chain 32—preferably by the force of gravity alone—in thatthe two partial fillets 12, 14 fold sideways and downwards. Optionally,however, the partial fillets 12, 14 may also be brought into an openedposition actively.

After the first cut by the cutting apparatus 21 and before the secondcut by the cutting apparatus 24, the residual/remaining red meat ispreferably automatically detected again in the fish fillet 10 to beprocessed using a means 27 for detecting red meat. In the second andthird automatic cut, the fish fillet 10 is preferably held on thesegment chain 32 by means of devices 48, 49 for holding the fish down.The cutting apparatuses 24 and 25, just as the cutting apparatus 21, maybe directly controlled. Preferably, however, the cutting apparatuses 21,24, 25 are controlled by the control device 26 via a robotic mechanism42, 68, 69.

All cuts are preferably made with circular knives 38, 39; 54, 55; 56, 57arranged in pairs, which are set in a V-shape at an angle to each other.The second and the third cut at least can also be made with a Whizardknife. Preferably, the cutting, first of the ventral-side partial stripand then the dorsal-side partial strip or vice versa, is repeated in afourth and fifth cut by additional cutting apparatuses along thetransport path, the red meat in the fish fillet 10 to be processed beingautomatically detected again before the fourth and fifth cut using ameans 71 for detecting red meat. Preferably, the partial strips removedby automatic cutting are automatically extracted by suction.

Especially preferably, the method is carried out using an arrangement 18according to one or more of claims 1 to 18.

1-25. (canceled)
 26. An arrangement, designed and configured forautomatically removing a strip consisting of dark meat from a fishfillet, comprising: a conveying unit for transporting the fish fillet tobe processed from an inlet area of the fish fillet into the arrangementto an outlet area of the fish fillet out of the arrangement in atransport direction along a transport path; and starting from the inletarea in the direction of the outlet area successively along thetransport path; a first means for detecting dark meat in the fish filletto be processed; a first cutting apparatus for removing a middle,central partial strip of dark meat from the fish fillet; a means foropening up the fish fillet freed from the middle partial strip in such amanner that the cut surfaces of a ventral-side partial strip of darkmeat still attached to the fish fillet and of a dorsal-side partialstrip of dark meat still attached to the fish fillet, which are producedby the first cutting apparatus, point upwards away from the conveyingunit; a cutting unit for removing the ventral-side and the dorsal-sidepartial strips of dark meat from the fish fillet, the cutting unitcomprising a second cutting apparatus for removing the ventral-sidepartial strip and a third cutting apparatus for removing the dorsal-sidepartial strip; a control device, at least the means for detecting darkmeat and the three cutting apparatuses being connected to the controldevice in such a manner that all cuts are made based on the data and/orinformation determined by the means for detecting dark meat.
 27. Thearrangement according to claim 26, further comprising a second means fordetecting remaining dark meat in the fish fillet to be processed isdisposed, in the transport direction, between the means for opening upthe fish fillet and the cutting unit, the second means for detectingremaining dark meat also being connected to the control device.
 28. Thearrangement according to claim 26, further comprising a handling devicefor automatically aligning the fish fillet to be processed on theconveying unit is disposed, in the transport direction, between thefirst means for detecting dark meat, which is arranged in the inletarea, and the second cutting apparatus for removing the middle, centralpartial strip, the handling device also being connected to the controldevice.
 29. The arrangement according to claim 28, wherein the handlingdevice comprises a robotic mechanism with an alignment tool.
 30. Thearrangement according to claim 26, wherein the first cutting apparatuscomprises two circular knives set in a V-shape at a fixed angle to eachother and a drive for the circular knives, wherein the two circularknives are vertically and horizontally adjustable.
 31. The arrangementaccording to claim 26, further comprising a robotic mechanism, the firstcutting apparatus being arranged on the robotic mechanism by means ofwhich a position of the first cutting apparatus relative to theconveying unit is adjustable at least vertically and horizontally,wherein the robotic mechanism is also connected to the control device.32. The arrangement according to claim 26, wherein the second and thethird cutting apparatus each comprise two circular knives set in aV-shape at a fixed angle to each other and drives for the circularknives.
 33. The arrangement according to claim 26, wherein: the secondand the third cutting apparatus each comprise a knife carrier to whichtwo knife units are assigned; each knife unit comprises a circular knifeand a drive for rotationally driving the circular knife about a centralaxis of rotation; the two circular knives associated with each knifecarrier are set substantially in a V-shape to each other in a positionenclosing an angle; each knife carrier having an adjustable arrangementfor adjusting a size of the angle; an offset of the two central axes ofrotation of the circular knives associated with each knife carrier inthe transport direction is zero and the two knife units associated witheach knife carrier are adjustable exclusively synchronously with eachother.
 34. The arrangement according to claim 26, further comprising arobotic mechanism for each of the second and third cutting apparatus,wherein the second and the third cutting apparatus are arranged onebehind the other in the transport direction and each on a respective oneof the robotic mechanisms, wherein the robotic mechanisms are alsoconnected to the control device.
 35. The arrangement according to claim26, wherein: the conveying unit comprises a plurality of conveyingelements; a first one of the conveying elements is disposed in a regionof the first cutting apparatus and comprises a rotationally drivendouble belt with a gap running centrally and parallel to the transportdirection; and a second one of the conveying elements is disposed in aregion of the cutting unit and comprises a rotationally driven segmentchain which is triangular in cross-section.
 36. The arrangementaccording to claim 35, wherein: the double belt and the segment chainform a continuous conveying unit along the transport path in thetransport direction; and the segment chain engages in the double beltfrom below through the gap, at least in a transition region from thedouble belt to the segment chain, for transferring the fish fillets fromthe double belt.
 37. The arrangement according to claim 35, wherein thesegment chain forms the means for opening up the fish fillets.
 38. Thearrangement according to claim 35, wherein the segment chain hasspike-like protrusions on its upper side pointing in a direction of thecutting unit, for fastening the fish fillets on the segment chain. 39.The arrangement according to claim 35, further comprising devices forholding the fish down assigned to the segment chain at least in theregion of the cutting unit, in such a manner that the opened up fishfillets are fastened on both sides of the segment chain, between thedevices for holding the fish down and the segment chain, at least whenremoving the ventral-side and dorsal-side partial strips.
 40. Thearrangement according to claim 35, further comprising a fasteningprovided in a region of the double belt, in such a manner that the fishfillet is fastened on the double belt at least when removing the middle,central partial strip.
 41. The arrangement according to claim 26,further comprising a second cutting unit, corresponding to the firstcutting unit, arranged downstream, in the transport direction, of saidfirst cutting unit, the second cutting unit also comprising a second andthird cutting apparatus, wherein the second cutting unit is alsoconnected to the control device.
 42. The arrangement according to claim41, further comprising a third means for detecting dark meat arrangeddownstream of the first cutting unit and upstream of the second cuttingunit, in the transport direction, wherein the third means for detectingdark meat is also connected to the control device.
 43. The arrangementaccording to claim 26, further comprising a suction means for extractingthe removed partial strips by suction arranged in a region of eachcutting apparatus.
 44. A method for automatically removing a stripconsisting of dark meat from a fish fillet, comprising the followingsteps: automatically transporting the fish fillet to be processed alonga transport path from an inlet area to an outlet area in a transportdirection by means of a conveying unit; automatically detecting the darkmeat in the fish fillet to be processed using a means for detecting darkmeat; automatically cutting a middle, central partial strip of dark meatfrom the fish fillet using a first cutting apparatus; automaticallyopening up the fish fillet freed from the middle, central partial stripusing a means for opening up, in such a manner that cut surfaces of aventral-side partial strip of dark meat still attached to the fishfillet and a dorsal-side partial strip of dark meat still attached tothe fish fillet, which are formed when removing the middle, centralpartial strip, point upwards away from the conveying unit; andautomatically cutting the ventral-side and dorsal-side partial stripfrom the fish fillet using a second and a third cutting apparatus;wherein the cutting apparatuses are controlled using a control devicebased on data and/or information determined by the means for detectingdark meat.
 45. The method according to claim 44, wherein: the strip ofdark meat is automatically cut from the fish fillet in at least threesteps; first the middle, central partial strip is cut from the fishfillet; and subsequently first the ventral-side partial strip and thenthe dorsal-side partial strip or first the dorsal-side partial strip andthen the ventral-side partial strip of dark meat are cut from the fishfillet.
 46. The method according to claim 45, wherein the cutting, firstof the ventral-side partial strip and then the dorsal-side partial stripor vice versa, is repeated in a fourth and fifth step by additionalcutting apparatuses along the transport path, wherein the dark meat inthe fish fillet to be processed is automatically detected again beforethe fourth and fifth step using a means for detecting dark meat.
 47. Themethod according to claim 44, wherein each fish fillet is fastened tothe conveying unit during the cutting of the partial strips.
 48. Themethod according to claim 44, wherein all cuts of all partial strips aremade by circular knives set in a V-shape to each other.
 49. The methodaccording to claim 44, wherein the partial strips removed by cutting areextracted by suction.
 50. The method according to claim 44, wherein themethod is carried out with an arrangement claim 26.